CN106501994B

CN106501994B - Quantum dot light-emitting device, backlight module and display device

Info

Publication number: CN106501994B
Application number: CN201510565875.0A
Authority: CN
Inventors: 李富琳; 曹建伟; 黄顺明; 张登印
Original assignee: Qingdao Hisense Electronics Co Ltd
Current assignee: Hisense Visual Technology Co Ltd
Priority date: 2015-09-08
Filing date: 2015-09-08
Publication date: 2021-10-29
Anticipated expiration: 2035-09-08
Also published as: US9970630B2; US20170067604A1; CN106501994A

Abstract

The embodiment of the invention relates to the technical field of display, in particular to a quantum dot light-emitting device, a backlight module and a display device, and aims to solve the problem that quantum dots positioned right above an LED chip are prone to failure in the prior art. The quantum dot light-emitting device provided by the embodiment of the invention comprises a base; the light-emitting chip is arranged on the base; the quantum dot layer is arranged on the base, is positioned in the light-emitting direction of the light-emitting chip and has a gap with the light-emitting chip, wherein reflection dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and the reflection dots are at least distributed in the area of the quantum dot layer right opposite to the light-emitting chip.

Description

Quantum dot light-emitting device, backlight module and display device

Technical Field

The invention relates to the technical field of display, in particular to a quantum dot light source device, a backlight module and a display device.

Background

Color gamut is an index that describes the color rendition capability that a display can achieve. The current industry uses a backlight scheme in which blue light excites quantum dot materials to produce white light, which can reach the color gamut of 100% NTSC (National Television Standards Committee).

In the prior art, Quantum Dots (English: Quantum Dots) with different sizes can be excited to emit red light and green light with high purity by irradiating the Quantum Dots with blue light, and the red light and the green light are mixed with the residual pure blue light to obtain white light with high brightness. At present, when quantum dots are applied to a direct type display, a backlight module in the industry adopts a method of coating the quantum dots on a membrane, and the specific structure is as shown in fig. 1, wherein a light emitting chip 102 is arranged on a back plate 101, and blue light emitted from the light emitting chip 102 irradiates on the membrane 103 coated with the quantum dots, so that quantum dot materials on the membrane 103 coated with the quantum dots can be excited to emit red light and green light with high purity. In the above solution, since the quantum dot material is required to be coated on the entire diaphragm 103, the amount of quantum dots used is relatively large, resulting in a relatively high cost of the solution.

In order to solve the problem of high cost, another solution in the industry is to place quantum dots above a Light Emitting Diode (LED) chip as a point Light source, and fig. 2 exemplarily shows a structural schematic diagram of a backlight module using the point Light source. As shown in fig. 2a, a plurality of point light sources 202 are disposed on a back plate 201. The structure of each point light source 202 can refer to fig. 2b, and includes: LED chip 202a, and quantum dot layer 202b disposed over LED chip 202, in a manner that conserves the amount of quantum dots used.

However, since the light intensity of the LED chip 202a in each point light source 202 is lambertian, that is, the smaller the light emitting angle of the LED chip 202a, the higher the light power generated per unit area, and the light power irradiated to the quantum dot layer 202b per unit area with the smaller angle can reach 60-100W/cm². As shown in fig. 2b, the area of the quantum dot layer 202b opposite to the LED chip 202a receives a larger amount of light power than the area of the LED chip diagonally opposite thereto, and the area of the quantum dot layer receiving a larger amount of light power generates a higher temperature than the area of the quantum dot layer receiving a smaller amount of light power. Since quantum dot materials can be rendered ineffective under the influence of high temperatures, the quantum dot layer can withstand blue light irradiation to a limit of typically 5W/cm²Hereinafter, therefore, the quantum dot layer 202b directly above the LED chip 202a is more easily irradiated with blue light of high intensity, resulting in quantum dot failure.

Disclosure of Invention

The embodiment of the invention provides a quantum dot light-emitting device, a backlight module and a display device, and at least solves the problem that quantum dots positioned right above an LED chip are easy to lose effectiveness in the prior art.

The embodiment of the invention provides a quantum dot light-emitting device, which comprises:

a base;

the light-emitting chip is arranged on the base;

the quantum dot layer is arranged on the base, is positioned in the light-emitting direction of the light-emitting chip and has a gap with the light-emitting chip, wherein reflection dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and the reflection dots are at least distributed in the area of the quantum dot layer right opposite to the light-emitting chip.

Preferably, the base is in a groove shape, the light emitting chip is disposed at the bottom of the groove of the base, and the quantum dot layer is disposed at an opening of the groove of the base, wherein the base, the light emitting chip and the quantum dot layer are packaged into an integral structure.

Preferably, the inner wall of the groove of the base can reflect light.

Preferably, the reflection dots are distributed in the region defined by the whole quantum dot layer; on a straight line passing through the center of the region opposite to the light-emitting chip, the distance between any two adjacent reflection points is gradually increased from the center to the edge of the quantum dot layer.

Preferably, the reflection dots are distributed in a region defined by the whole quantum dot layer, and the size of the reflection dots becomes smaller from the center of the region directly opposite to the light emitting chip to the edge of the quantum dot layer.

Preferably, the reflection points are hemispheroid and are distributed on the quantum dot layer in a concentric circle shape, wherein the radius of each reflection point distributed on each concentric circle is equal, the radius of each reflection point distributed on each concentric circle decreases with the increase of the radius of each concentric circle, and the density of the plurality of reflection points distributed on each concentric circle decreases with the increase of the radius of each concentric circle.

Preferably, the quantum dot layer includes:

the quantum dot-based light-emitting diode comprises a first substrate, a second substrate, quantum dots and a water-oxygen isolation material, wherein the first substrate and the second substrate are oppositely arranged, and the water-oxygen isolation material is sealed between the first substrate and the second substrate and is positioned at the periphery of the quantum dots.

Preferably, the quantum dot material comprises red quantum dots, green quantum dots and resin; the light emitting chip is a blue light chip.

Preferably, the material of the reflection point comprises SiO₂、CaCO₃、TiO₂、BaSO₄One or more reflective materials.

Preferably, the reflection dots arranged on the quantum dot layer are printing type dots.

The embodiment of the invention provides a direct type backlight module, which comprises:

a back plate;

a plurality of the quantum dot light emitting devices provided in the above embodiments, the quantum dot light emitting devices being disposed on the backplane;

the optical film group is arranged in the light emitting direction of the quantum dot light emitting device.

An embodiment of the present invention provides a display device, including:

the direct type backlight module provided by the embodiment;

and the display panel is arranged in the light emergent direction of the direct type backlight module.

The embodiment of the present invention further provides a side-in type backlight module, which includes:

a reflective sheet;

the light guide plate is provided with a light incident surface, a light emergent surface and a reflecting surface, and the reflecting sheet is arranged on the reflecting surface of the light guide plate;

the quantum dot light-emitting device provided by the plurality of embodiments is arranged on one side of the light incident surface of the light guide plate;

and the optical diaphragm group is arranged in the direction of the light emergent surface of the light guide plate.

An embodiment of the present invention further provides a display device, including:

the lateral backlight module provided by the embodiment;

the display panel is arranged in the light emergent direction of the side-entry backlight module.

In the embodiment of the invention, the quantum dot layer is arranged on the base and positioned in the light-emitting direction of the light-emitting chip, and a gap is formed between the quantum dot layer and the light-emitting chip; therefore, the quantum dot layer can receive the irradiation light emitted from the light emitting chip. The reflection points are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and the reflection points are at least distributed in the right region of the quantum dot layer and the light-emitting chip. The reflection points arranged in the area just opposite to the light-emitting chip can reflect part of light from the area just opposite to the light-emitting chip, so that the light power of the quantum dot layer in the area just opposite to the light-emitting chip for receiving the light irradiated by the light-emitting chip is reduced, the problem that the quantum dot layer in the area just opposite to the light-emitting chip fails due to high temperature is avoided, and further, as the reflection points reflect the light in the positive direction of the light-emitting chip, the reflected light is transmitted to the quantum dot layer from the edge part of the quantum dot layer, so that the light received by the quantum dot layer in the quantum dot light-emitting device is relatively uniform.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a quantum dot coated film in the prior art;

FIG. 2a is a schematic diagram of a prior art point light source with a quantum dot layer;

FIG. 2b is a schematic diagram of a quantum dot layer disposed over the LED chip of FIG. 2 a;

FIG. 3 is a schematic view of an optical structure of a backlight module according to an embodiment of the present invention;

fig. 4a is a schematic structural diagram of a quantum dot light-emitting device according to an embodiment of the present invention;

fig. 4b is a schematic optical path diagram illustrating that light emitted by the light emitting chip provided in the embodiment of the present invention is reflected by the reflection point and then irradiates the quantum dot layer again;

FIG. 4c is a schematic diagram of a quantum dot layer structure according to an embodiment of the present invention;

FIG. 5a is a schematic diagram of a distribution of reflection dots on a quantum dot layer according to an embodiment of the present invention;

fig. 5b is a schematic cross-sectional view of a plurality of reflection dots distributed on any straight line in fig. 5a on a quantum dot layer;

fig. 6a is a schematic diagram illustrating a distribution of reflection dots in a quantum dot layer according to an embodiment of the present invention;

fig. 6b is a schematic cross-sectional view of a plurality of reflection dots disposed on the quantum layer in fig. 6 a;

FIG. 7 is a schematic diagram of another distribution of reflection dots on a quantum dot layer according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of another distribution of reflection dots on a quantum dot layer according to an embodiment of the present invention;

FIG. 9 is a schematic view of a direct-type backlight module according to an embodiment of the present invention;

fig. 10 is a schematic structural view of a side-entry backlight module according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a display device according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of another display device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the quantum dot light-emitting device provided by the embodiment of the invention, the reflection dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and the reflection dots are at least distributed in the region where the quantum dot layer is opposite to the light-emitting chip, so that the problem of nonuniform received light irradiation in the prior art is solved.

In the embodiment of the invention, the technical terms are as follows:

1. backlight source: the light source with uniformly distributed in-plane brightness is provided for a Thin Film Transistor Liquid Crystal Display (TFT-LCD for short).

2. Direct Type backlight mode (English is: Direct or Bottom Back-Light Type): the luminous bodies are directly arranged below the display screen, and a large number of luminous bodies are uniformly distributed on the whole backlight surface.

3. The diffusion sheet is divided into an upper diffusion sheet and a lower diffusion sheet, the diffusion sheet positioned on one side of the light source is called a lower diffusion sheet, the diffusion sheet positioned on one side of the display screen is called an upper diffusion sheet, and the lower diffusion sheet mainly has the functions of enabling light rays to be subjected to diffuse reflection through the diffusion coating, enabling the light rays to be uniformly distributed and ensuring the uniform brightness in the plane of the backlight source; the upper diffusion sheet serves to prevent the prism patterns on the prism sheet from being scratched by direct contact with the display screen, and is also called a protective sheet.

4. The prism sheet is positioned between the upper diffusion sheet and the lower diffusion sheet and is used as a light condensing device, and the light coming out of the lower diffusion sheet is concentrated in a certain angle range to be emitted by utilizing total reflection and refraction, so that the brightness in the visual field range is improved.

5. The reflective sheet reflects light rays of a Cold Cathode Fluorescent Lamp (CCFL for short) or an LED, so that the light rays enter the light guide plate or the diffusion sheet, thereby improving the light utilization rate of the backlight source.

6. Quantum dot: is a nanoparticle composed of a compound of a group II-VI or group III-V element. The quantum size effect of the quantum dots causes great change of the photoelectric properties of the semiconductor quantum dots, and the quantum size effect generated when the size of the semiconductor quantum dot particles is smaller than the bohr radius of excitons changes the energy level structure of the semiconductor material, so that the semiconductor material has a continuous energy band structure and is converted into a discrete energy level structure with molecular characteristics. By utilizing the phenomenon, the semiconductor quantum dots with different particle diameters can be prepared in the same reaction to generate light emission with different frequencies, so that various light emitting colors can be conveniently regulated and controlled.

Fig. 3 is a schematic cross-sectional view schematically illustrating an optical structure of a direct type backlight module suitable for use in an embodiment of the invention. As shown in fig. 3, the backlight module includes: a back plate 301, point light sources 302, a lower diffusion sheet 303, prism sheets 304, and an upper diffusion sheet 305. The point light source 302 may be an LED light emitting chip, a cold cathode fluorescent tube, or an Electroluminescence (EL), which is not listed here.

As shown in fig. 3, light from the point light source 302 is irradiated onto the lower diffusion sheet 303, light passing through the lower diffusion sheet 303 is uniformly irradiated onto the prism sheet 304, and the prism sheet 304 concentrates the relatively dispersed light from the lower diffusion sheet 303 in a certain angle range and emits the light with the upper diffusion sheet, thereby providing a light source with uniform in-plane brightness distribution for the display screen. In the above embodiment, if the light source employs the CCFL or LED, a reflective sheet needs to be designed at the bottom of the backlight, i.e. on the back plate 301 in fig. 3, to reflect the light emitted from the CCFL or LED. The common LED television adopts a blue LED chip and yellow fluorescent powder to form white light, or an ultraviolet (near ultraviolet) LED and red, green and blue fluorescent powder to form white light, or independent red, green and blue LEDs are integrally packaged to form the white light. However, the purity of the three primary colors of red, green and blue generated by the above method is insufficient, so that the colors of the three primary colors of red, green and blue which can be mixed are less, and the color gamut represented by the three primary colors of red, green and blue is narrower, so that most of the blue, green and part of the red on the display screen cannot be accurately displayed.

Research shows that the quality of the color gamut of the display screen is related to a plurality of indexes of a television, wherein one important index is a backlight source. From the above explanation of the technical terms, it can be known that the backlight mainly provides a light source with uniformly distributed in-plane brightness for the display screen, and the main factor of the influence of the backlight on the color gamut of the display screen depends on the purities of the red, green and blue light waves. When the quantum dots are excited by electricity or light, monochromatic light with different colors but very high purity can be emitted according to the radius of the quantum dots. The high-purity white light can be obtained by mixing the red light, the green light and the blue light with high purity, so that the color gamut of the display screen is high, and most of the blue light, the green light and the red light can be accurately displayed on the display screen.

In the prior art, a quantum dot layer is generally arranged right above an LED chip, and a quantum dot fails when encountering high temperature, so that when the quantum dot is applied to a backlight source, the quantum dot layer and the LED chip may have large optical power received by a region right above the LED chip due to the placement position of the quantum dot layer right above the LED chip, and a temperature that the quantum dot cannot bear is generated, so that the quantum dot fails, and thus the display effect of a display screen is affected.

Based on the above analysis, it is considered that quantum dots have a problem of failure at high temperature. In the embodiment of the invention, the method for setting the reflection point on the quantum dot layer in the region opposite to the quantum dot layer and the light-emitting chip is provided, the reflection point which is arranged in the region opposite to the quantum dot layer and the light-emitting chip is utilized to reflect the light irradiated to the region opposite to the quantum dot layer and the light-emitting chip, and the problems that the quantum dot in the region opposite to the light-emitting chip receives large optical power, the temperature which the quantum dot cannot bear is generated, the quantum dot is invalid, the receiving illumination of a light source device is affected, and the display effect of a display screen is affected are solved.

Fig. 4a schematically illustrates a structure of a quantum dot light emitting device according to an embodiment of the present invention. The quantum dot light-emitting device can be used as a point light source of a backlight module.

Referring to fig. 4a, a quantum dot light emitting device provided in the embodiment of the present invention mainly includes: a base 401, a light emitting chip 402, a quantum dot layer 403, and reflective dots 404. Wherein, the light emitting chip 402 is disposed on the base 401; the quantum dot layer 403 is disposed on the base 401 in the light-emitting direction of the light-emitting chip 402, and a gap is formed between the quantum dot layer 403 and the light-emitting chip 402; the quantum dot layer 403 is provided with reflection dots 404 on a surface opposite to the light emitting chip 402, and the reflection dots 404 are distributed at least in a region where the quantum dot layer 403 faces the light emitting chip 402.

The reflection dots 404 are distributed at least in the region where the quantum dot layer 403 faces the light-emitting chip 402, and this means that the reflection dots 404 may be distributed only in the region where the light-emitting chip 402 faces, or may be distributed in a larger region on the quantum dot layer 403, and may be distributed over the entire quantum dot layer 403, for example. In addition, the term "distribution" generally refers to a plurality of reflection points distributed in a certain region, wherein a certain reflection point may be spaced apart from other reflection points or may be adjacent to one or some other reflection points, as long as part of the light rays irradiated to the above-mentioned region (region where the reflection points are distributed) of the quantum dot layer 403 can pass through the gap between the reflection points, and part of the light rays can be reflected by the reflection points.

In the embodiment of the invention, because the reflection points are arranged on the surface of the quantum dot layer opposite to the light-emitting chip and are at least distributed in the dead zone of the quantum dot layer and the light-emitting chip, namely, the reflection points arranged in the dead zone of the light-emitting chip can reflect part of light from the dead zone of the light-emitting chip, the light power irradiated by the light-emitting chip received by the quantum dot layer in the dead zone of the light-emitting chip is reduced, the problem that the quantum dot layer in the dead zone of the light-emitting chip fails due to high temperature is avoided, and further, the reflected light is transmitted to the quantum dot layer from the edge part of the quantum dot layer due to the reflection of the light in the positive direction of the light-emitting chip by the reflection points, so that the light received by the quantum dot layer in the quantum dot light-emitting device is relatively uniform.

Referring to fig. 4a, in the embodiment of the invention, the base 401 is in a groove shape, the light emitting chip 402 is disposed at the bottom of the groove of the base 401, and the quantum dot layer is disposed at the opening of the groove of the base 401. The base 401, the light emitting chip 402 and the quantum dot layer 403 are packaged into an integral structure to form a first quantum dot light emitting device. In the prior art, since the distance between the light emitting chip 402 and the quantum dot layer 403 is relatively short, when the light from the light emitting chip 402 directly irradiates the quantum dot layer in the region directly opposite to the light emitting chip 402, the quantum dot material in the region directly opposite to the light emitting chip tends to fail. In the embodiment of the present invention, since the reflection dots 404 are disposed in the region of the quantum dot layer opposite to the light emitting chip, and the reflection dots 404 reflect the light emitted from the light emitting chip 402, the light path of the light emitted from the light emitting chip 402 can be changed, and the light emitted from the light emitting chip 402 can be reflected to the base 401. Thereby avoiding the problem of quantum dot material failure in the region where the quantum dot layer 403 is opposite to the light-emitting chip 402.

In an embodiment of the present invention, a plurality of light emitting chips 402 may be disposed at the bottom of the groove of the submount 401 while the quantum dot layer 403 is disposed at the opening of the groove of the submount. The opening of the groove of the base can correspond to a light guide plate, that is, the quantum dot layer 403 is disposed on the lower side of the light guide plate. In the embodiment of the present invention, the opening of the groove may also correspond to an optical membrane set, that is, the quantum dot layer 403 is disposed on the lower side of the optical membrane set. In the above embodiment, since the quantum dot layer is relatively far from the light-emitting chip, the quantum dot material of the quantum dot layer in the region directly opposite to the light-emitting chip does not fail due to the irradiation of the light-emitting chip. Because the reflection points are arranged in the region, which is just opposite to the light-emitting chip, of the quantum dot layer, the reflection points can reflect the light from the region, which is just opposite to the light-emitting chip, so that the transmission direction of the light emitted by the light-emitting chip is changed, and the light, which is just opposite to the region, of the light-emitting chip is reflected to the base, and therefore the light irradiating the quantum dot layer is more uniform.

In the embodiment of the invention, in order to improve the utilization rate of the light emitted by the light-emitting chip, the inner wall of the groove of the base can reflect light. Illustratively, the inner walls of the grooves of the susceptor are coated with a reflective layer. As another example, the base may be made of a material having a property of reflecting visible light, and further, may have properties of resisting blue light radiation and resisting high temperature.

Fig. 4b schematically shows a light path of light emitted from the light emitting chip in the light emitting device. Referring to fig. 4b, the reflection dots 404 provided on the quantum dot layer 403 in the region opposite to the light emitting chip 402 reflect light emitted from the light emitting chip 402 onto the base 401, and since the base 401 can reflect light, the base 401 can reflect light reflected from the reflection dots 404 again, so that the light reflected by the reflection dots 404 is reflected by the base 401 and then irradiated again onto the quantum dot layer 402. By adopting the method, the light emitted by the light-emitting chip 402 can be uniformly irradiated on the quantum dot layer 403, and the problem that the quantum dot layer 403 and the light-emitting chip directly opposite region receive high-temperature irradiation to cause quantum dot failure is avoided. Further, since the base 401 has the characteristics of blue light radiation resistance and high temperature resistance, even if the intensity of light reflected by the reflection point 404 is relatively large, the base 401 does not fail, thereby affecting the re-reflection of the light reflected by the reflection point 404. Preferably, the composition material of the base may be an Epoxy Molding Compound (EMC) material. In the embodiment of the present invention, the material of the base is not particularly limited.

In the embodiment of the invention, in order to better protect the quantum dots, a layer of substrate is respectively arranged above and below the quantum dots, and the quantum dots are sealed in the upper substrate and the lower substrate. The packaging process generally adopted for sealing the quantum dots on the upper substrate and the lower substrate is laser melting or a fire burning method. In practical applications, if the quantum dots are directly sealed on the upper and lower substrates, the quantum dots close to the sealing dots of the upper and lower substrates may fail due to the high temperature. In the embodiment of the invention, in order to avoid the problem that the quantum dot material fails due to the influence of high temperature in the sealing process of the quantum dot material, the water and oxygen isolation material is arranged around the quantum dot while the quantum dot is sealed on the upper substrate and the lower substrate.

Fig. 4c schematically shows a structure diagram of a quantum dot layer provided by the embodiment of the invention. Referring to fig. 4c, the quantum dot layer includes: a first substrate 403-1, a second substrate 403-2, quantum dots 403-3, and a water-oxygen barrier material 403-4 around the quantum dots 403-3. Wherein the first substrate 403-1 and the second substrate 403-2 are disposed opposite to each other, and the quantum dots 403-3 and the water and oxygen barrier material 403-4 around the quantum dots are sealed between the first substrate 403-1 and the second substrate 403-2. Preferably, the first substrate and the second substrate may be glass substrates. In the embodiment of the present invention, the materials of the first substrate and the second substrate are not particularly limited.

The water and oxygen isolation materials are arranged around the quantum dot layer, so that the quantum dots are saved; on one hand, the problem that the quantum dots fail due to high temperature during high-temperature sealing is avoided; and in the other method, the problem that the quantum dots are invalid due to the fact that the quantum dots meet water or oxygen is solved. Preferably, the water oxygen barrier material may be selected from silicon dioxide materials. In the embodiment of the present invention, the constituent materials of the water oxygen barrier material are not particularly limited.

In the embodiment of the invention, the quantum dot material comprises the red quantum dot, the green quantum dot and the resin, and the quantum dot has high light efficiency and narrow emission spectral line, so that light from the light emitting chip can be efficiently converted into red light or green light close to monochromatic light, the color gamut is further improved, and the display quality of a picture is improved. Because the quantum dots contained in the quantum dot layer have different sizes, the light from the light emitting chip can be converted into light with different colors, and the size of the red light quantum dot is about 7nm, and the size of the green light quantum dot is about 3 nm.

As the core-shell type quantum dots are used for converting the light-emitting chip, the quantum dots with the core-shell structure have more excellent light-emitting characteristics from the aspects of absorption and emission spectrum, can obviously reduce the surface defects of the nano particles, and greatly improve the light-emitting efficiency, so that the core-shell type red light quantum dots and the core-shell type green light quantum dots are beneficial to improving the light-emitting efficiency. Preferably, the red and green quantum dots may be core-shell type quantum dots. In the embodiment of the present invention, the material of the red quantum dots and the green quantum dots is not specifically limited.

Because the blue light has shorter wavelength and higher energy, the red light quantum dots and the green light quantum dots can be excited and converted into red light and green light respectively. In the embodiment of the invention, the light emitting chip can preferably select the light emitting chip emitting blue light, and the blue light emitted by the light emitting chip is close to monochromatic light, so that the blue light emitting chip is adopted to irradiate the red quantum dots and the green quantum dots, the color gamut can be further improved, and the display quality of a picture can be improved.

In the embodiment of the invention, in order to better protect the quantum dot layer in the region opposite to the light-emitting chip from the problem of quantum dot material failure caused by high-intensity light irradiation emitted by the light-emitting chip, the surface of the quantum dot layer opposite to the light-emitting chip is provided with the reflection dots, and the reflection dots are at least distributed in the region of the quantum dot layer opposite to the light-emitting chip. The reflection point may reflect light emitted from the light emitting chip and irradiated to the reflection point. Further, the reflection point is composed of a material having a reflection property. Preferably, the material of the reflection point comprises SiO₂、CaCO₃、TiO₂、BaSO₄One or more reflective materials. In the embodiment of the present invention, the constituent material of the reflection point is not specifically limited.

The reflecting dots are preferably formed by printing the reflecting dots on the quantum dot layer, that is, by printing the ink on the quantum dot layer to form the reflecting dots, which is called a printing type dot. The ink may be a material with high reflection and scattering properties, and may include one or more of the above reflective materials. In the embodiment of the present invention, a specific method for disposing the reflection dots to the quantum dot layer is not limited.

In the embodiment of the present invention, since the surface of the quantum dot layer opposite to the light emitting chip further includes the second substrate, the reflective dots are disposed on the surface of the quantum layer opposite to the light emitting chip, and the reflective dots are actually disposed on the second substrate, and the second substrate is generally made of glass.

Because quantum dot layer and luminescence chip all set up on the base, and quantum dot layer is located luminescence chip's light-emitting direction, all need adopt transparent, and have sticky material with quantum dot layer from the upside fix on the base. Preferably, the material having transparency and viscosity may be a silicone gel. In the embodiment of the present invention, the material that is transparent and adhesive is not particularly limited.

Based on the same inventive concept and different distribution of the reflection dots on the quantum dot layer, the embodiments of the present invention further include at least the following specific embodiments, specifically referring to the first to the fourth embodiments.

Example one

A quantum dot light-emitting device provided with at least a reflection dot in a region where a quantum dot layer faces a light-emitting chip according to an embodiment of the present invention is further described with reference to fig. 5a and 5 b. Fig. 5a is a schematic diagram illustrating a distribution of reflective dots on a quantum dot layer according to an embodiment of the present invention; fig. 5b is a schematic cross-sectional view of a plurality of reflection dots distributed on any straight line in fig. 5a on a quantum dot layer.

The embodiments of the present invention only further limit the distribution of the reflective dots on the quantum dot layer, and reference may be made to the above embodiments for other structures of the quantum dot light emitting device.

In the embodiment of the present invention, referring to fig. 5a, the reflection dots are distributed in the region defined by the whole quantum dot layer, that is, the reflection dots are distributed in both the facing region of the light emitting chip and the region other than the facing region. And on a straight line passing through the center of the region opposite to the light-emitting chip, the distance between any two adjacent reflection points is gradually increased from the center to the edge of the quantum dot layer.

Referring to fig. 5a, taking the reflection point 501 of the light emitting chip facing the center point of the area as an example, the reflection points are distributed on a straight line formed by any one of the reflection points adjacent to the reflection point 501. Moreover, a plurality of reflection points distributed on any straight line are symmetrically distributed with the reflection point 501 as the center.

For example, a plurality of reflection points are distributed on a straight line 51 passing through the reflection point 501, and the plurality of reflection points are distributed on both the left and right sides of the reflection point 501. The distance between the reflection point 501 and the adjacent reflection point 502 is d1, and since the reflection point 502 and the reflection point 502-1 are respectively symmetrically distributed with the reflection point 501 and have equal distances from the reflection point 501, the distance between the reflection point 502-1 and the reflection point 501 can also be determined to be d 1; the distance between the reflection points 503 adjacent to the reflection point 502 is d2, since the reflection point 503-1 and the reflection point 503 are symmetrically distributed with the reflection point 501 respectively, and the distances from the reflection point 501 are equal, and the distances from the reflection point 502 and the reflection point 502-1 to the reflection point 501 are both d1, it can be determined that the distance between the reflection point 503-1 and the reflection point 502-1 is d2, and d2 is greater than d 1; according to the above rule, it is further determined that the distance between the reflection point 504 and the reflection point 503 is d3, and the distance between the reflection point 504-1 and the reflection point 503-1 is also d3, and d3 is greater than d 2; the distance between the reflection point 505 and the reflection point 504 is d4, and the distance between the reflection point 505-1 and the reflection point 504-1 is also d4, and d4 is greater than d 3; the distance between the reflection point 506 and the reflection point 505 is d5, and the distance between the reflection point 506-1 and the reflection point 505-1 is also d5, and d5 is greater than d 4; the distance between the reflection point 507 and the reflection point 506 is d6, and the distance between the reflection point 507-1 and the reflection point 506-1 is also d6, and d6 is greater than d 5; the distance between the reflection point 508 and the reflection point 507 is d7, and the distance between the reflection point 508-1 and the reflection point 507-1 is also d7, and d7 is greater than d 6.

From the above analysis and as shown in fig. 5a, it was confirmed that the distance between any two adjacent reflection points distributed on any straight line of the reflection points of the region facing the light-emitting chip gradually increases from the center of the region facing the light-emitting chip to the edge of the quantum dot layer. For example, the distance d1 between the reflection point 501 and the reflection point 502 is smaller than the distance d2 between the reflection point 502 and the reflection point 503; the distance d2 between reflection point 503 and reflection point 502 is less than the distance d3 between reflection point 504 and reflection point 503; likewise, the distance d6 between the reflection point 506 and the reflection point 507 is less than the distance d7 between the reflection point 508 and the reflection point 507.

Referring to fig. 5b, a plurality of reflection dots are disposed on the surface of the quantum dot layer 5 opposite to the light emitting chip (not shown in the figure), and the plurality of reflection dots are symmetrically distributed around a reflection dot 501 which is opposite to the central point of the region of the light emitting chip. For example, the distance between the reflection point 502 and the reflection point 501 is d1, and since the reflection point 502 and the reflection point 502-1 are symmetrically distributed with the reflection point 501 as the center, the distance between the reflection point 502-1 and the reflection point 501 is also d 1; the distance between the reflection point 503 and the reflection point 502 is d2, since the emission point 503 and the reflection point 503-1 are symmetrically distributed with the reflection point 501 as the center, and the distances between the reflection point 502 and the reflection point 502-1 and the reflection point 501 are d1, it can be determined that the distance between the reflection point 503-1 and the reflection point 5021 is also d2, and d2 is greater than d 1; further, the distance between the reflection point 504 and the reflection point 503 is d3, the distance between the reflection point 504-1 and the reflection point 503-1 is d3, the distance between the reflection point 505 and the reflection point 504 is d4, the distance between the reflection point 505-1 and the reflection point 504-1 is d4, the distance between the reflection point 506 and the reflection point 505 is d5, the distance between the reflection point 506-1 and the reflection point 505-1 is d5, and d5 is greater than d4, d4 is greater than d3, and d3 is greater than d 2.

According to the above analysis, it can be determined that, by the reflection points distributed on any straight line of the reflection points of the light emitting chip facing the center of the region, since the distance between the reflection point of the light emitting chip facing the center of the region and any one of the adjacent reflection points is smaller than the distance between any other two adjacent reflection points on any straight line of the reflection points of the light emitting chip facing the region, and the distance between any two adjacent reflection points is larger and larger as the distance from the reflection point of the light emitting chip facing the center of the region is longer, and since the light intensity of the light emitting chip is lambertian, the light power per unit area of small angle is larger than the light power per unit area of large angle. In the embodiment of the invention, even if the light intensity of the light-emitting chip is lambertian, the problems of high light power in a unit area of a small angle and more photons passing in unit time exist, so that the light emitted by the light-emitting chip is received by the area, which is right opposite to the light-emitting chip, of the quantum dot layer, and the light intensity emitted by the light-emitting chip is received by the peripheral area of the quantum dot layer. Since the quantum dot layer in the region directly opposite to the light-emitting chip has more reflection dots than the quantum dot layer in the peripheral region, the probability of reflecting light from the light-emitting chip at the reflection dots in the region directly opposite to the light-emitting chip is higher than the probability of reflecting light from the light-emitting chip at the reflection dots in the peripheral region of the quantum layer. When light emitted by the light emitting chip is irradiated on the reflecting point of the area opposite to the light emitting chip, the light is reflected by the reflecting point, the light path of the light emitted by the light emitting chip is changed, the light from the light emitting chip is reflected to the base, the base has a reflecting function, the light from the light emitting chip is reflected by the base again, and the light reflected again can enter the quantum dot layer from the peripheral area of the quantum dot. By adopting the method provided by the embodiment of the invention, the quantum dot failure of the quantum dot layer caused by the high-power irradiation of the light-emitting chip can be avoided, and the quantum dot layer can uniformly receive the light emitted by the light-emitting chip.

In the embodiment of the invention, the plurality of quantum dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip on a straight line passing through the center of the region opposite to the light-emitting chip. Preferably, any one straight line passes through the center of the region directly opposite to the light-emitting chip, a reflection point is arranged at the center of the region directly opposite to the light-emitting chip, and the plurality of reflection points on any one straight line are symmetrically distributed with the center of the reflection point in the region directly opposite to the light-emitting chip. Furthermore, any straight line passes through the center of the area directly opposite to the light-emitting chip, and the center of the area directly opposite to the light-emitting chip can also have no reflection point, but a plurality of reflection points on any straight line are also symmetrically distributed by taking the area directly opposite to the light-emitting chip as the center. In the embodiment of the invention, no specific limitation is made on whether the region opposite to the light-emitting chip is provided with the reflection point.

In the embodiment of the invention, a plurality of quantum dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and a plurality of reflection dots are symmetrically distributed by taking one reflection dot which is opposite to the center of the light-emitting chip. Preferably, the plurality of quantum dots provided on the surface of the quantum layer opposite to the light emitting chip are shaped like a hemisphere. Further, the shape of the plurality of quantum dots provided on the surface of the quantum layer and the light emitting chip row pair may be irregular. In the embodiment of the present invention, the shape of the plurality of quantum dots provided on the surface of the quantum layer and the light emitting chip row pair is not specifically defined.

In the embodiment of the present invention, the plurality of quantum dots are disposed on the surface of the quantum dot layer opposite to the light emitting chip, and when the quantum dots are in a hemispherical shape, it is preferable that the radii of the plurality of quantum dots are equal; further, the radii of the multiple quanta may also be unequal. In the embodiment of the present invention, the radius of the plurality of quantum dots is not specifically limited.

In the embodiment of the invention, a plurality of quantum dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and a plurality of reflection dots are symmetrically distributed by taking one reflection dot which is opposite to the central point of the area of the light-emitting chip as the center. Preferably, the distance between any two adjacent reflection points distributed on the same straight line can be increased progressively according to a set value from the center of the region directly opposite to the light-emitting chip to the edge of the quantum dot layer; furthermore, the distance between any two adjacent reflection points distributed on the same straight line from the center of the region directly opposite to the light-emitting chip to the edge of the quantum dot layer can also be increased progressively according to any numerical value; further, the distances between the reflective dots distributed on the same straight line may be increased in accordance with the increasing state of the quantum dot layer from the center of the region facing the light emitting chip to the edge of the quantum dot layer, but there is no limitation on whether the distance between any two adjacent reflective dots is increased, for example, the distance between the quantum dot 1 of the region facing the light emitting chip and the quantum dot 2 adjacent to the quantum dot 1 is l2, the distance between the quantum dot 3 adjacent to the quantum dot 2 is also l2, but the distance between the quantum dot 4 and the quantum dot 5 is l4, where l4 is greater than l 2. In the embodiment of the present invention, the distance between any two adjacent reflection points distributed on the same straight line is not specifically limited, and the incremental value from the center of the region directly opposite to the light emitting chip to the edge of the quantum dot layer is not specifically limited.

Example two

A quantum dot light-emitting device provided with at least a reflection dot in a region where a quantum dot layer faces a light-emitting chip according to an embodiment of the present invention is further described with reference to fig. 6a and 6 b. Fig. 6a is a schematic diagram illustrating a distribution of reflective dots on a quantum dot layer according to an embodiment of the present invention; fig. 6b is a schematic cross-sectional view of a plurality of reflection dots disposed on the quantum layer in fig. 6 a.

In the embodiment of the present invention, referring to fig. 6a, the reflection dots are distributed in the region defined by the whole quantum dot layer, that is, the reflection dots are distributed in both the facing region of the light emitting chip and the region other than the facing region. The size of the reflection point is gradually reduced from the center of the region opposite to the light-emitting chip to the edge of the quantum dot layer.

Referring to fig. 6a, taking the reflection point 601 of the light emitting chip opposite to the center point of the area as an example, when the quantum dot is spherical. The reflection point 601 is located at the center point of the region where the quantum dot layer and the light emitting chip are opposite, the radius of the reflection point 601 is r1 (not shown in the figure), the radii of two reflection points 602 and two reflection points 602-1 adjacent to the reflection point 601 are equal, and are both r2 (not shown in the figure), and r1 is greater than r 2; the radius of the reflection point 603 adjacent to the reflection point 602 is r3 (not shown in the figure), correspondingly, the radius of the reflection point 603-1 adjacent to the reflection point 602-1 is also r3, and r2 is greater than r 3; according to the above rule, it is determined that the radius of the reflection point 605 adjacent to the reflection point 604 is r5 (not shown in the figure), and accordingly, the radius of the reflection point 605-1 adjacent to the reflection point 604-1 is also r5, and r4 (not shown in the figure) is greater than r 5.

Referring to fig. 6b, a plurality of reflection dots are disposed on a surface of the quantum dot layer 6 opposite to the light emitting chip (not shown in the figure), and the radius of the plurality of reflection dots becomes gradually smaller from the center of the region facing the light emitting chip to the edge portion of the quantum dot layer. For example, the radius r1 of reflection point 601 is greater than the radius r2 of reflection point 602 and reflection point 602-1; radius r2 of reflection point 602 is greater than radius r3 of reflection point 603, and radius r2 of reflection point 602-1 is greater than radius r3 of reflection point 603-1; similarly, the radius r4 of the reflection point 604 is greater than the radius r5 of the reflection point 605; accordingly, the radius r4 of reflection point 604-1 is greater than the radius r5 of reflection point 605-1.

According to the above analysis, it can be determined that, since the radius of the reflection point in the region directly opposite to the light-emitting chip is larger than the radius of any reflection point adjacent to the reflection point in the region directly opposite to the light-emitting chip, and the radius of the reflection point farther from the reflection point in the region directly opposite to the light-emitting chip is smaller, the light power per unit area of a small angle is larger than the light power per unit area of a large angle because the light intensity of the light-emitting chip is lambertian. In the embodiment of the invention, even if the light intensity of the light-emitting chip is lambertian, the problems of high light power in a unit area of a small angle and more photons passing in unit time exist, so that the light emitted by the light-emitting chip is received by the area, which is right opposite to the light-emitting chip, of the quantum dot layer, and the light intensity emitted by the light-emitting chip is received by the peripheral area of the quantum dot layer. Because the surface of the quantum dot layer opposite to the light-emitting chip is provided with the reflection point, the radius of the reflection point of the area opposite to the light-emitting chip is larger than the radius of any reflection point adjacent to the reflection point of the area opposite to the light-emitting chip, and the reflection point has a reflection function, the light emitted by the light-emitting chip and received by the area opposite to the quantum dot layer and the light-emitting chip can be reflected. Because the radius of the reflection point arranged on the quantum dot layer in the region opposite to the light-emitting chip is larger than that of the reflection point arranged in the peripheral region of the quantum dot layer, the probability of reflecting the light from the light-emitting chip by the reflection point in the region opposite to the quantum dot layer and the light-emitting chip is higher than that of reflecting the light from the light-emitting chip by the reflection point in the peripheral region of the quantum layer. When light emitted by the light emitting chip is irradiated on the reflecting point of the area opposite to the light emitting chip, the light is reflected by the reflecting point, the light path of the light emitted by the light emitting chip is changed, the light from the light emitting chip is reflected to the base, the base has a reflecting function, the light from the light emitting chip is reflected by the base again, and the light reflected again can enter the quantum dot layer from the peripheral area of the quantum dot. By adopting the method provided by the embodiment of the invention, the quantum dot failure of the quantum dot layer caused by the high-power irradiation of the light-emitting chip can be avoided, and the quantum dot layer can uniformly receive the light emitted by the light-emitting chip.

In the embodiment of the present invention, the plurality of quantum dots are disposed on the surface of the quantum dot layer opposite to the light emitting chip, and preferably, the plurality of quantum dots disposed on the surface of the quantum layer opposite to the light emitting chip row are shaped like a hemisphere. Further, the shape of the plurality of quantum dots provided on the surface of the quantum layer and the light emitting chip row pair may be an irregular shape. In the embodiment of the present invention, the shape of the plurality of quantum dots provided on the surface of the quantum layer facing the light-emitting chip is not specifically defined.

In the embodiment of the present invention, the plurality of quantum dots are disposed on the surface of the quantum dot layer opposite to the light emitting chip, and preferably, the radius of the reflection dot may be regularly decreased from the center of the region facing the light emitting chip to the edge of the quantum dot layer according to a set value. Further, the radius of the reflection dot may be decreased from the center of the region directly opposite to the light emitting chip to the edge of the quantum dot layer by an arbitrary value. Further, the radius of the reflection dot may be changed from the center of the region opposite to the light emitting chip to the edge of the quantum dot layer as a whole according to a decreasing rule, but there is no limitation on whether the radius of any adjacent reflection dot decreases from the center of the region opposite to the light emitting chip to the edge, for example, the radius of the quantum dot 1 in the region opposite to the light emitting chip is r1, the radius of the quantum dot 2 adjacent to the quantum dot 1 is r2, the radius of the quantum dot 3 adjacent to the quantum dot 2 is also r2, but the radius of the quantum dot 5 is r4, where r1 is greater than r2, and r2 is greater than r 4. In the embodiment of the present invention, the value of the radius of the plurality of quantum dots disposed on the surface opposite to the light-emitting chip, which decreases from the center of the region directly opposite to the light-emitting chip to the edge of the quantum dot layer, is not particularly limited.

In the embodiment of the invention, the plurality of quantum dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and when the radius of the reflection dot from the center of the region opposite to the light-emitting chip to the edge of the quantum dot layer can be regularly decreased according to a set value, preferably, the distance between any two adjacent reflection dots from the center of the region opposite to the light-emitting chip to the edge of the quantum dots is equal. In the embodiment of the invention, the distance between any two adjacent reflection points from the center of the region opposite to the light-emitting chip to the edge of the quantum point is not specifically limited.

EXAMPLE III

A quantum dot light-emitting device provided with at least a reflection dot in a region where a quantum dot layer faces a light-emitting chip according to an embodiment of the present invention is further described with reference to fig. 7. Fig. 7 is a schematic diagram illustrating a distribution of reflective dots on a quantum dot layer according to an embodiment of the present invention.

In the embodiment of the present invention, referring to fig. 7, the reflection dots are distributed on the quantum dot layer in a hemispherical shape and in a concentric circle shape. The radius of each reflection point distributed on each concentric circle is equal, the radius of each reflection point distributed on each concentric circle is reduced along with the increase of the radius of each concentric circle, and the density of the plurality of reflection points distributed on each concentric circle is reduced along with the increase of the radius of each concentric circle.

Referring to fig. 7, taking a reflection point 701 of the light emitting chip disposed opposite to the center of the region as an example, a radius of the reflection point 701 is r1 (not shown in the figure), the reflection point 701 is used as a center of a circle, and a plurality of reflection points are disposed on a second concentric circle 702 adjacent to the reflection point 701, wherein the radius of the plurality of reflection points disposed on the concentric circle 702 is r2 (not shown in the figure), and r1 is greater than r 2; a plurality of reflection points are arranged on a third concentric circle 703 adjacent to the second concentric circle 702 by taking the reflection point 701 as a center of a circle, and the radius of the plurality of reflection points arranged on the concentric circle 703 is r3 (not shown in the figure), wherein r3 is greater than r 2; further, the density of the reflection points disposed on the concentric circle 703 is less than that of the reflection points disposed on the concentric circle 702, wherein in the embodiment of the present invention, the density refers to a ratio of the number of the reflection points distributed on the same circle to the circumference. According to the above rule, it is determined that the radius of the plurality of reflection points provided on the concentric circle 705 is r5 (not shown in the figure), the radius r5 of the reflection points provided on the concentric circle 705 is smaller than the radius r4 (not shown in the figure) of the reflection points provided on the concentric circle 704, and the radius of the concentric circle 705 is larger than the radius of the concentric circle 704, that is, the density of the reflection points provided on the concentric circle 705 is smaller than the density of the reflection points provided on the concentric circle 704.

From the above analysis, it was confirmed that a plurality of reflection points are disposed on the surface of the quantum dot layer opposite to the light emitting chip, since the plurality of reflection points are concentrically distributed on the quantum dot layer and the radii of the respective reflection points distributed on each concentric circle are equal, and the radius of the reflection point distributed on each concentric circle decreases as the radius of each concentric circle increases, the density of the plurality of reflection points distributed on each concentric circle decreases as the radius of each concentric circle increases, and since the light intensity of the light emitting chip is lambertian, the light power per unit area of a small angle is greater than that per unit area of a large angle. In the embodiment of the invention, even if the light intensity of the light-emitting chip is lambertian, the problems of high light power in a unit area of a small angle and more photons passing in unit time exist, so that the light emitted by the light-emitting chip is received by the area, which is right opposite to the light-emitting chip, of the quantum dot layer, and the light intensity emitted by the light-emitting chip is received by the peripheral area of the quantum dot layer. Because the surface of the quantum dot layer opposite to the luminescent chip is provided with the reflecting dots, the reflecting dots have the reflecting function, and the light emitted by the luminescent chip can be received by the dead-against area of the quantum dot layer and the luminescent chip for reflection, and in the embodiment of the invention, the reflecting dots arranged on the quantum dot layer have the following distribution characteristics: (1) the radius of a central reflection point of the area opposite to the light-emitting chip is larger than that of any reflection point arranged on other concentric circles taking the reflection point as the center of a circle; (2) the density of the reflection points arranged on other concentric circles taking the reflection point at the center of the region directly opposite to the light-emitting chip as the center of the circle is reduced along with the increase of the radius of the concentric circles. Therefore, the probability of reflecting the light from the light emitting chip by the reflection points in the region of the quantum dot layer opposite to the light emitting chip is higher than the probability of reflecting the light from the light emitting chip by the reflection points in the region of the quantum dot layer periphery. When light emitted by the light emitting chip is irradiated on the reflecting point of the area opposite to the light emitting chip, the light is reflected by the reflecting point, the light path of the light emitted by the light emitting chip is changed, the light from the light emitting chip is reflected to the base, the base has a reflecting function, the light from the light emitting chip is reflected by the base again, and the light reflected again can enter the quantum dot layer from the peripheral area of the quantum dot. By adopting the method provided by the embodiment of the invention, the quantum dot material failure caused by the high-power irradiation of the luminescent chip of the quantum dot layer can be avoided, and the quantum dot layer can uniformly receive the irradiation light emitted by the luminescent chip.

In the embodiment of the present invention, the radius of the reflection dots distributed on each concentric circle decreases as the radius of each concentric circle increases, and preferably, the radius of the reflection dots from the center of the region opposite to the light emitting chip to the edge of the quantum dot layer may be regularly decreased by a set value. Further, the radius of the reflection dot may be decreased from the center of the region directly opposite to the light emitting chip to the edge of the quantum dot layer by an arbitrary value. Further, the radius of the reflection point may be changed from the center of the region opposite to the light emitting chip to the edge of the quantum dot layer as a whole according to a decreasing rule, but there is no limitation on whether the radius of the reflection point on any adjacent concentric circle from the center of the region opposite to the light emitting chip to the edge decreases. For example, the radius of the quantum dot 1 in the opposite region of the light emitting chip is r1, the radius of the quantum dot 2 on the concentric circle 2 adjacent to the quantum dot 1 is r2, and the radius of the quantum dot 3 on the concentric circle 3 adjacent to the concentric circle 2 is also r2, but the radius of the quantum dot 5 on the concentric circle 5 is r4, wherein r1 is greater than r2, and r2 is greater than r 4. In the embodiment of the present invention, the value of the radius of the plurality of quantum dots disposed on the surface opposite to the light-emitting chip, which decreases from the center of the region directly opposite to the light-emitting chip to the edge of the quantum dot layer, is not particularly limited.

In the embodiment of the present invention, the density of the plurality of reflection points distributed on each concentric circle decreases as the radius of each concentric circle increases, and preferably, the density of the plurality of reflection points distributed on each concentric circle regularly decreases by a set value as the radius of each concentric circle increases. Further, the density of the plurality of reflection points distributed on each concentric circle may be decreased by an arbitrary value as the radius of each concentric circle increases. Further, the density of the plurality of reflection points distributed on each concentric circle decreases as the radius of each concentric circle increases, but whether the radius of the reflection point on any adjacent concentric circle decreases or not is not particularly limited. In the embodiment of the present invention, the density of the plurality of reflection points distributed on each concentric circle decreases with the increase of the radius of each concentric circle, which is not particularly limited.

Example four

A quantum dot light-emitting device provided with at least a reflection dot in a region where a quantum dot layer and a light-emitting chip are opposite to each other according to an embodiment of the present invention will be further described with reference to fig. 8. Fig. 8 is a schematic diagram illustrating a distribution of reflective dots on a quantum dot layer according to an embodiment of the present invention.

In the embodiment of the present invention, referring to fig. 8, the reflection dots are distributed on the quantum dot layer in a hemispherical shape and in a concentric circle shape. Wherein the radius of the reflection points distributed on each concentric circle is equal, the radius of the reflection points distributed on each concentric circle decreases with the increase of the radius of each concentric circle, the density of the reflection points distributed on each concentric circle decreases with the increase of the radius of each concentric circle, and the distance between each concentric circle gradually increases from the center to the edge of the quantum dot layer.

Referring to fig. 8, taking a reflection point 801 arranged at the center of the region opposite to the light emitting chip as an example, the radius of the reflection point 801 is r1 (not shown in the figure), and a plurality of reflection points are arranged on a second concentric circle 802 adjacent to the reflection point 801 and centered on the reflection point 801, the radii of the plurality of reflection points are r2 (not shown in the figure), and r1 is greater than r 2; further, the distance between any point on the concentric circle 802 and the reflection point 801 is d 1. A plurality of reflection points are arranged on a third concentric circle 803 adjacent to the second concentric circle 802 by taking the reflection point 801 as a center, the radius of the plurality of reflection points is r3 (not shown in the figure), and r3 is larger than r 2; further, the shortest distance between any point on the concentric circle 803 and the concentric circle 802 is d2, and d2 is greater than d 1; the density of the reflection points disposed on the concentric circle 803 is less than that of the reflection points disposed on the concentric circle 802, and in the embodiment of the present invention, the density refers to a ratio of the number of the reflection points distributed on the same circle to the circumference. According to the above rule, it is determined that the radius of the plurality of reflection points provided on the concentric circle 805 is r5 (not shown in the figure), and the radius r5 of the reflection points provided on the concentric circle 805 is smaller than the radius r4 of the reflection points provided on the concentric circle 804; further, the shortest probability between any point on the concentric circle 805 and the concentric circle 804 is d4, d4 is greater than d3, and the density of the reflection points disposed on the concentric circle 805 is less than the density of the reflection points disposed on the concentric circle 804.

From the above analysis, it was confirmed that a plurality of reflection dots are disposed on a surface of the quantum dot layer opposite to the light emitting chip, since the plurality of reflection dots are concentrically distributed on the quantum dot layer, the radii of the respective reflection dots distributed on each concentric circle are equal, the radius of the reflection dots distributed on each concentric circle decreases as the radius of each concentric circle increases, the density of the plurality of reflection dots distributed on each concentric circle decreases as the radius of each concentric circle increases, and the distance between each concentric circle gradually increases from the center to the edge of the quantum dot layer. Because the light intensity of the light-emitting chip is in Lambert distribution, the light power on a small-angle unit area is larger than that on a large-angle unit area. In the embodiment of the invention, even if the light intensity of the light-emitting chip is lambertian, the problems of high light power in a unit area of a small angle and more photons passing in unit time exist, so that the light emitted by the light-emitting chip is received by the area, which is right opposite to the light-emitting chip, of the quantum dot layer, and the light intensity emitted by the light-emitting chip is received by the peripheral area of the quantum dot layer. Because the surface of the quantum dot layer opposite to the luminescent chip is provided with the reflecting dots, the reflecting dots have the reflecting function, and the light emitted by the luminescent chip can be received by the dead-against area of the quantum dot layer and the luminescent chip for reflection, and in the embodiment of the invention, the reflecting dots arranged on the quantum dot layer have the following distribution characteristics: (1) the radius of a central reflection point of the area opposite to the light-emitting chip is larger than that of any reflection point arranged on other concentric circles taking the reflection point as the center of a circle; (2) the density of the reflection points arranged on other concentric circles taking the reflection point at the center of the region directly opposite to the light-emitting chip as the center of the circle is reduced along with the increase of the radius of the concentric circles. (3) The distance between each concentric circle taking the reflection point of the light-emitting chip opposite to the center of the area as the center is gradually increased from the center to the edge of the quantum dot layer. Therefore, the probability of reflecting the light from the light emitting chip by the reflection points in the region of the quantum dot layer opposite to the light emitting chip is higher than the probability of reflecting the light from the light emitting chip by the reflection points in the region of the quantum dot layer periphery. When light emitted by the light emitting chip is irradiated on the reflecting point of the area opposite to the light emitting chip, the light is reflected by the reflecting point, the light path of the light emitted by the light emitting chip is changed, the light from the light emitting chip is reflected to the base, the base has a reflecting function, the light from the light emitting chip is reflected by the base again, and the light reflected again can enter the quantum dot layer from the peripheral area of the quantum dot. By adopting the method provided by the embodiment of the invention, the quantum dot material failure caused by the high-power irradiation of the luminescent chip of the quantum dot layer can be avoided, and the quantum dot layer can uniformly receive the irradiation light emitted by the luminescent chip.

As shown in fig. 9, a direct type backlight module provided in an embodiment of the present invention includes: a back plate 901, a quantum dot light emitting device 902 and an optical film set 903. The quantum dot light-emitting device 901 is any quantum dot light-emitting device in the embodiments of the present invention, the quantum dot light-emitting device 902 is disposed on the back plate 901, and the optical film set 903 is disposed in the light-emitting direction of the quantum dot light-emitting device 902.

As shown in fig. 10, an edge-lit backlight module provided in an embodiment of the present invention includes: the light guide plate comprises a quantum dot light emitting device 1001, a reflecting sheet 1002, a light guide plate 1003 and an optical film set 1004. The quantum dot light emitting device 1001 is any quantum dot light emitting device in the embodiment of the present invention, the quantum dot light emitting device 1001 is disposed on one side of the light guide plate 1003, the reflective sheet 1002 is disposed below the light guide plate 1003, and the optical film set 1004 is disposed in the light emitting direction of the light guide plate 1003.

As shown in fig. 11, a display device according to an embodiment of the present invention includes a direct type backlight module 1101 and a display panel 1102 according to an embodiment of the present invention, wherein the display panel 1102 is disposed in a light emitting direction of the direct type backlight module 1101.

As shown in fig. 12, another display device provided in the embodiment of the present invention includes a side-in type backlight module 1201 provided in the embodiment of the present invention and a display panel 1202, where the display panel 1202 is disposed in a light emitting direction of the side-in type backlight module 1201.

In the embodiment of the invention, the quantum dot layer is arranged on the base and positioned in the light-emitting direction of the light-emitting chip, and a gap is formed between the quantum dot layer and the light-emitting chip; therefore, the quantum dot layer can receive the irradiation light emitted from the light emitting chip. Because the reflection points are arranged on the surface of the quantum dot layer opposite to the light-emitting chip and are at least distributed in the positive alignment area of the quantum dot layer and the light-emitting chip, the reflection points in the positive alignment area of the light-emitting chip can reflect the light from the positive direction of the light-emitting chip, thereby avoiding the problem that the light source device has uneven receiving illumination caused by the failure of the quantum dot layer in the positive alignment area of the light-emitting chip due to high-temperature irradiation.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A quantum dot light emitting device, comprising:

a base;

the light-emitting chip is arranged on the base;

the quantum dot layer is arranged on the base, is positioned in the light-emitting direction of the light-emitting chip and has a gap with the light-emitting chip, wherein reflection dots are arranged on the surface of the quantum dot layer opposite to the light-emitting chip, and the reflection dots are at least distributed in the area of the quantum dot layer opposite to the light-emitting chip;

the distribution of the reflection points comprises at least one of the following ways:

the reflection points are hemispheroid and are distributed on the quantum dot layer in a concentric circle shape, wherein the radius of each reflection point distributed on each concentric circle is equal, the radius of each reflection point distributed on each concentric circle is reduced along with the increase of the radius of each concentric circle, and the density of the plurality of reflection points distributed on each concentric circle is reduced along with the increase of the radius of each concentric circle;

the reflection points are distributed in the area defined by the whole quantum dot layer; on a straight line passing through the center of the region opposite to the light-emitting chip, the distance between any two adjacent reflection points is gradually increased from the center to the edge of the quantum dot layer;

the reflection points are distributed in the area defined by the whole quantum dot layer, and the size of the reflection points is gradually reduced from the center of the area opposite to the light-emitting chip to the edge of the quantum dot layer.

2. The quantum dot light-emitting device according to claim 1,

the base is in a groove shape, the light-emitting chip is arranged at the bottom of the groove of the base, the quantum dot layer is arranged at the opening of the groove of the base, and the base, the light-emitting chip and the quantum dot layer are packaged into an integral structure.

3. The quantum dot light emitting device of claim 2,

the inner wall of the groove of the base can reflect light.

4. A quantum dot light emitting device according to claim 1, wherein the quantum dot layer comprises:

5. The quantum dot light-emitting device according to claim 1, wherein the quantum dot material comprises red quantum dots, green quantum dots, and a resin; the light emitting chip is a blue light chip.

6. The quantum dot light-emitting device of claim 1, wherein the material of the reflective dots comprisesSiO₂、CaCO₃、TiO₂、BaSO₄One or more reflective materials.

7. A quantum dot light emitting device according to claim 1, wherein the reflective dots provided on the quantum dot layer are printed dots.

8. A direct type backlight module is characterized by comprising:

a back plate;

a plurality of quantum dot light emitting devices of any of claims 1 to 7 disposed on the backsheet;

9. A side-in backlight module, comprising:

a reflective sheet;

a plurality of quantum dot light emitting devices according to any one of claims 1 to 7, disposed on the light incident surface side of the light guide plate;

10. A display device, comprising:

the direct type backlight module of claim 8;

11. A display device, comprising:

the edge-lit backlight module of claim 9;